NMR studies of non-freezing water in randomly packed beds of porous particles

Abstract

NMR water proton transverse relaxation time distributions are shown to provide valuable information about the distribution of ice and nonfreezing water in complex heterogeneous systems. In a model system consisting of randomly packed Sephadex beads the NMR data confirm that ice inside the porous Sephadex beads coexists as a two phase system with unfrozen dextran gel. The NMR relaxation technique is shown to provide complementary information to both differential scanning calorimetry and cryomicroscopy.